Abstract

Background

In dogs, the gastric Helicobacter spp. have been well studied, but there is little information regarding the other
parts of the alimentary system. The incidence of Helicobacter spp. infection in dogs is largely unknown and to our knowledge there are no data
about their potential pathogenic role. In light of these considerations, the aims
of this study were (i) to assess the prevalence of Helicobacter spp. in colonic biopsies of healthy and symptomatic stray dogs also (ii) we isolate
and characterize helicobacters in canine colonic biopsies to compare the commonly
used tests for the identification of Helicobacter spp. and to determine the occurrence of these species in dogs.

Methods

Tissues from fifteen stray dogs (8 males and 7 females, age 6 months –10 years) were
used in this study. From each stray dog, multiple colonic biopsies were taken for
PCR. Biopsies for PCR of cecum and colon were immediately frozen and stored at -20°C
until DNA extraction. Samples for histological examination were fixed in 10% neutral
buffered formalin and embedded in paraffin wax.

Results

In the cecum and colon, Helicobacter spp. DNA was detected in all dogs. H.canis, H.bizzozeronii, H. bilis, H.felis, H.salomonis and H.pylori Identified by specific polymerase chain reaction. Histopathology demonstrated that
Helicobacter organisms were localized within the surface mucus and the intestinal crypts. Dogs
with heavy Helicobacter spp. colonization were significantly in younger as well as had a higher level of
mucosal fibrosis/atrophy than dogs with uncolonized or poorly colonized biopsies (p < 0.05).

Conclusions

We have indicated that the crypts of the cecum and colon of healthy and symptomatic
dogs are heavily colonized by Helicobacter spp.. Combined molecular and histological approaches demonstrated that enterohepatic
Helicobacter spp. infection is rather common in colonic biopsies of healthy and symptomatic stray
dogs, with Helicobacter spp. specialy H. canis, H.bizzozeroni, H.billis, H.felis and H. salomonis identified as the most common species.